This chapter describes various applications of Voice over Wireless LAN (VoWLAN) systems. Real-world examples and case studies provide you with a solid understanding of how VoWLAN can benefit a company. Details are also given about tangible benefits and expected return on investment (ROI).

Examples of the systems that VoWLANs can replace include the following:

Wired telephones

Cellular telephones

Two-way radios

With VoWLANs, people can use VoWLAN phones to communicate by voice wirelessly with others inside and outside a facility. The experience is very similar to using a traditional wired telephone, except the user is free to move about the building. Furthermore, a VoWLAN phone can operate from many of the growing Wi-Fi hotspots, enabling a person to make use of the same mobile phone while within or away from the office or home. Some cellular phones incorporate VoWLAN capability, which enables users to make calls over traditional cellular networks when no wireless local-area network (wireless LAN) is available.

The local-only configuration (part A of Figure 1-1), which is similar to two-way radios, consists of a wireless LAN that merely enables a user to talk to other users directly connected to the network. This supports a mix of wireless and wired VoIP telephones. For example, a clerk looking for a part in a warehouse may use a VoWLAN handset to communicate with a manager sitting at a desk and using a wired VoIP phone.

More advanced VoWLAN systems (Parts B and C of Figure 1-1), however, allow users to place actual telephone calls from their VoWLAN handsets. The telephone traffic can travel over the Internet or the Public Switched Telephone Network (PSTN). With these two models, the use of the system is virtually the same as a traditional telephone. For example, a sales agent in her home office in Ohio may dial a phone number on her VoWLAN phone to call a customer in California.

The primary benefit of VoWLAN solutions is cost savings. For instance, according to recent studies, federal, state, and local agencies could achieve savings of $4.5 billion annually by making telephone calls over the Internet. In addition, VoWLAN systems are easier to deploy and allow flexible communications. VoWLAN plays a critical role in realizing these savings by mobilizing the workforce.